This invention relates to a turn signal system for a vehicle which comprises means to indicate a right or left turn of the vehicle and to automatically cancel the turn signal indication.
With a direction-indicating device for vehicles, there have been proposed various means for returning a direction-indicating member to the original position after said member has completed the indication of turning directions. With a four-wheeled automobile, the return of a direction-indicating member can be easily effected through utilization of the automatic returning action of a steering wheel or handle after it has been used to divert the course of the automobile to the right or left. In the case of a motorcycle, however, difficulties arise in utilizing the return of the steering handle in order to terminate a direction-indicating action.
To date, a direction-indicating device has been proposed for motorcycles which determines a point of time at which a direction-indicating operation should terminate from a distance covered by a motorcycle or a length of time for which the motorcycle has traveled after completion of the indication of a direction. Then, automatic return of said direction-indicating device is affected. However, the prior art direction-indicating device has only taken into acount a distance covered by a motorcycle or a length of time for which the vehicle travels after operation of the direction-indicating device, presenting difficulties in practical application. For example, a direction-indicating device which is designed to automatically return to the original position when a motorcycle has run a prescribed distance after indication of a direction is completed has the drawback that where a motorcycle travels fast, for example, in outrunning the preceding vehicle, the direction-indicating device sometimes undesirably regains the original position before said outrun is fully brought to an end, possibly giving rise to a traffic accident. Another type of direction-indicating device which is designed to regain the original position when a motorcycle has traveled for a certain length of time after operation of said device is finished also has the drawback that where the motorcycle runs slowly, for example, in making a left turn at a cross-road and moreover another straight-moving vehicle follows said motorcycle, a left turn display device is possibly extinguished before said motorcycle completes the left turn, making it necessary to carry out the indication of the left turn over again in order to avoid a possible collision with the following vehicle.
The above-mentioned prior art direction-indicating device is designed to regain the original position by electrical means, for example, by an electromagnetic solenoid, or by mechanical means, for example, a link mechanism. In either case, the conventional turn signal indicating device is defective in that the device is of complicated arrangement, becomes bulky, and, is not optimally applicable to a motorcycle.